xref: /openbmc/linux/init/Kconfig (revision dc52ddc0)
180daa560SRoman Zippelconfig ARCH
280daa560SRoman Zippel	string
380daa560SRoman Zippel	option env="ARCH"
480daa560SRoman Zippel
580daa560SRoman Zippelconfig KERNELVERSION
680daa560SRoman Zippel	string
780daa560SRoman Zippel	option env="KERNELVERSION"
880daa560SRoman Zippel
9face4374SRoman Zippelconfig DEFCONFIG_LIST
10face4374SRoman Zippel	string
11b2670eacSPaolo 'Blaisorblade' Giarrusso	depends on !UML
12face4374SRoman Zippel	option defconfig_list
13face4374SRoman Zippel	default "/lib/modules/$UNAME_RELEASE/.config"
14face4374SRoman Zippel	default "/etc/kernel-config"
15face4374SRoman Zippel	default "/boot/config-$UNAME_RELEASE"
1673531905SSam Ravnborg	default "$ARCH_DEFCONFIG"
17face4374SRoman Zippel	default "arch/$ARCH/defconfig"
18face4374SRoman Zippel
19ff0cfc66SAl Boldimenu "General setup"
201da177e4SLinus Torvalds
211da177e4SLinus Torvaldsconfig EXPERIMENTAL
221da177e4SLinus Torvalds	bool "Prompt for development and/or incomplete code/drivers"
231da177e4SLinus Torvalds	---help---
241da177e4SLinus Torvalds	  Some of the various things that Linux supports (such as network
251da177e4SLinus Torvalds	  drivers, file systems, network protocols, etc.) can be in a state
261da177e4SLinus Torvalds	  of development where the functionality, stability, or the level of
271da177e4SLinus Torvalds	  testing is not yet high enough for general use. This is usually
281da177e4SLinus Torvalds	  known as the "alpha-test" phase among developers. If a feature is
291da177e4SLinus Torvalds	  currently in alpha-test, then the developers usually discourage
301da177e4SLinus Torvalds	  uninformed widespread use of this feature by the general public to
311da177e4SLinus Torvalds	  avoid "Why doesn't this work?" type mail messages. However, active
321da177e4SLinus Torvalds	  testing and use of these systems is welcomed. Just be aware that it
331da177e4SLinus Torvalds	  may not meet the normal level of reliability or it may fail to work
341da177e4SLinus Torvalds	  in some special cases. Detailed bug reports from people familiar
351da177e4SLinus Torvalds	  with the kernel internals are usually welcomed by the developers
361da177e4SLinus Torvalds	  (before submitting bug reports, please read the documents
371da177e4SLinus Torvalds	  <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
381da177e4SLinus Torvalds	  <file:Documentation/BUG-HUNTING>, and
391da177e4SLinus Torvalds	  <file:Documentation/oops-tracing.txt> in the kernel source).
401da177e4SLinus Torvalds
411da177e4SLinus Torvalds	  This option will also make obsoleted drivers available. These are
421da177e4SLinus Torvalds	  drivers that have been replaced by something else, and/or are
431da177e4SLinus Torvalds	  scheduled to be removed in a future kernel release.
441da177e4SLinus Torvalds
451da177e4SLinus Torvalds	  Unless you intend to help test and develop a feature or driver that
461da177e4SLinus Torvalds	  falls into this category, or you have a situation that requires
471da177e4SLinus Torvalds	  using these features, you should probably say N here, which will
481da177e4SLinus Torvalds	  cause the configurator to present you with fewer choices. If
491da177e4SLinus Torvalds	  you say Y here, you will be offered the choice of using features or
501da177e4SLinus Torvalds	  drivers that are currently considered to be in the alpha-test phase.
511da177e4SLinus Torvalds
521da177e4SLinus Torvaldsconfig BROKEN
531da177e4SLinus Torvalds	bool
541da177e4SLinus Torvalds
551da177e4SLinus Torvaldsconfig BROKEN_ON_SMP
561da177e4SLinus Torvalds	bool
571da177e4SLinus Torvalds	depends on BROKEN || !SMP
581da177e4SLinus Torvalds	default y
591da177e4SLinus Torvalds
601da177e4SLinus Torvaldsconfig LOCK_KERNEL
611da177e4SLinus Torvalds	bool
621da177e4SLinus Torvalds	depends on SMP || PREEMPT
631da177e4SLinus Torvalds	default y
641da177e4SLinus Torvalds
651da177e4SLinus Torvaldsconfig INIT_ENV_ARG_LIMIT
661da177e4SLinus Torvalds	int
67dd673bcaSAdrian Bunk	default 32 if !UML
68dd673bcaSAdrian Bunk	default 128 if UML
691da177e4SLinus Torvalds	help
7034ad92c2SRandy Dunlap	  Maximum of each of the number of arguments and environment
7134ad92c2SRandy Dunlap	  variables passed to init from the kernel command line.
721da177e4SLinus Torvalds
731da177e4SLinus Torvalds
741da177e4SLinus Torvaldsconfig LOCALVERSION
751da177e4SLinus Torvalds	string "Local version - append to kernel release"
761da177e4SLinus Torvalds	help
771da177e4SLinus Torvalds	  Append an extra string to the end of your kernel version.
781da177e4SLinus Torvalds	  This will show up when you type uname, for example.
791da177e4SLinus Torvalds	  The string you set here will be appended after the contents of
801da177e4SLinus Torvalds	  any files with a filename matching localversion* in your
811da177e4SLinus Torvalds	  object and source tree, in that order.  Your total string can
821da177e4SLinus Torvalds	  be a maximum of 64 characters.
831da177e4SLinus Torvalds
84aaebf433SRyan Andersonconfig LOCALVERSION_AUTO
85aaebf433SRyan Anderson	bool "Automatically append version information to the version string"
86aaebf433SRyan Anderson	default y
87aaebf433SRyan Anderson	help
88aaebf433SRyan Anderson	  This will try to automatically determine if the current tree is a
896e5a5420SRobert P. J. Day	  release tree by looking for git tags that belong to the current
906e5a5420SRobert P. J. Day	  top of tree revision.
91aaebf433SRyan Anderson
92aaebf433SRyan Anderson	  A string of the format -gxxxxxxxx will be added to the localversion
936e5a5420SRobert P. J. Day	  if a git-based tree is found.  The string generated by this will be
94aaebf433SRyan Anderson	  appended after any matching localversion* files, and after the value
956e5a5420SRobert P. J. Day	  set in CONFIG_LOCALVERSION.
96aaebf433SRyan Anderson
976e5a5420SRobert P. J. Day	  (The actual string used here is the first eight characters produced
986e5a5420SRobert P. J. Day	  by running the command:
996e5a5420SRobert P. J. Day
1006e5a5420SRobert P. J. Day	    $ git rev-parse --verify HEAD
1016e5a5420SRobert P. J. Day
1026e5a5420SRobert P. J. Day	  which is done within the script "scripts/setlocalversion".)
103aaebf433SRyan Anderson
1041da177e4SLinus Torvaldsconfig SWAP
1051da177e4SLinus Torvalds	bool "Support for paging of anonymous memory (swap)"
1069361401eSDavid Howells	depends on MMU && BLOCK
1071da177e4SLinus Torvalds	default y
1081da177e4SLinus Torvalds	help
1091da177e4SLinus Torvalds	  This option allows you to choose whether you want to have support
1101da177e4SLinus Torvalds	  for so called swap devices or swap files in your kernel that are
1111da177e4SLinus Torvalds	  used to provide more virtual memory than the actual RAM present
1121da177e4SLinus Torvalds	  in your computer.  If unsure say Y.
1131da177e4SLinus Torvalds
1141da177e4SLinus Torvaldsconfig SYSVIPC
1151da177e4SLinus Torvalds	bool "System V IPC"
1161da177e4SLinus Torvalds	---help---
1171da177e4SLinus Torvalds	  Inter Process Communication is a suite of library functions and
1181da177e4SLinus Torvalds	  system calls which let processes (running programs) synchronize and
1191da177e4SLinus Torvalds	  exchange information. It is generally considered to be a good thing,
1201da177e4SLinus Torvalds	  and some programs won't run unless you say Y here. In particular, if
1211da177e4SLinus Torvalds	  you want to run the DOS emulator dosemu under Linux (read the
1221da177e4SLinus Torvalds	  DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
1231da177e4SLinus Torvalds	  you'll need to say Y here.
1241da177e4SLinus Torvalds
1251da177e4SLinus Torvalds	  You can find documentation about IPC with "info ipc" and also in
1261da177e4SLinus Torvalds	  section 6.4 of the Linux Programmer's Guide, available from
1271da177e4SLinus Torvalds	  <http://www.tldp.org/guides.html>.
1281da177e4SLinus Torvalds
129a5494dcdSEric W. Biedermanconfig SYSVIPC_SYSCTL
130a5494dcdSEric W. Biederman	bool
131a5494dcdSEric W. Biederman	depends on SYSVIPC
132a5494dcdSEric W. Biederman	depends on SYSCTL
133a5494dcdSEric W. Biederman	default y
134a5494dcdSEric W. Biederman
1351da177e4SLinus Torvaldsconfig POSIX_MQUEUE
1361da177e4SLinus Torvalds	bool "POSIX Message Queues"
1371da177e4SLinus Torvalds	depends on NET && EXPERIMENTAL
1381da177e4SLinus Torvalds	---help---
1391da177e4SLinus Torvalds	  POSIX variant of message queues is a part of IPC. In POSIX message
1401da177e4SLinus Torvalds	  queues every message has a priority which decides about succession
1411da177e4SLinus Torvalds	  of receiving it by a process. If you want to compile and run
1421da177e4SLinus Torvalds	  programs written e.g. for Solaris with use of its POSIX message
143b0e37650SRobert P. J. Day	  queues (functions mq_*) say Y here.
1441da177e4SLinus Torvalds
1451da177e4SLinus Torvalds	  POSIX message queues are visible as a filesystem called 'mqueue'
1461da177e4SLinus Torvalds	  and can be mounted somewhere if you want to do filesystem
1471da177e4SLinus Torvalds	  operations on message queues.
1481da177e4SLinus Torvalds
1491da177e4SLinus Torvalds	  If unsure, say Y.
1501da177e4SLinus Torvalds
1511da177e4SLinus Torvaldsconfig BSD_PROCESS_ACCT
1521da177e4SLinus Torvalds	bool "BSD Process Accounting"
1531da177e4SLinus Torvalds	help
1541da177e4SLinus Torvalds	  If you say Y here, a user level program will be able to instruct the
1551da177e4SLinus Torvalds	  kernel (via a special system call) to write process accounting
1561da177e4SLinus Torvalds	  information to a file: whenever a process exits, information about
1571da177e4SLinus Torvalds	  that process will be appended to the file by the kernel.  The
1581da177e4SLinus Torvalds	  information includes things such as creation time, owning user,
1591da177e4SLinus Torvalds	  command name, memory usage, controlling terminal etc. (the complete
1601da177e4SLinus Torvalds	  list is in the struct acct in <file:include/linux/acct.h>).  It is
1611da177e4SLinus Torvalds	  up to the user level program to do useful things with this
1621da177e4SLinus Torvalds	  information.  This is generally a good idea, so say Y.
1631da177e4SLinus Torvalds
1641da177e4SLinus Torvaldsconfig BSD_PROCESS_ACCT_V3
1651da177e4SLinus Torvalds	bool "BSD Process Accounting version 3 file format"
1661da177e4SLinus Torvalds	depends on BSD_PROCESS_ACCT
1671da177e4SLinus Torvalds	default n
1681da177e4SLinus Torvalds	help
1691da177e4SLinus Torvalds	  If you say Y here, the process accounting information is written
1701da177e4SLinus Torvalds	  in a new file format that also logs the process IDs of each
1711da177e4SLinus Torvalds	  process and it's parent. Note that this file format is incompatible
1721da177e4SLinus Torvalds	  with previous v0/v1/v2 file formats, so you will need updated tools
1731da177e4SLinus Torvalds	  for processing it. A preliminary version of these tools is available
17437a4c940SS.Çağlar Onur	  at <http://www.gnu.org/software/acct/>.
1751da177e4SLinus Torvalds
176c757249aSShailabh Nagarconfig TASKSTATS
177c757249aSShailabh Nagar	bool "Export task/process statistics through netlink (EXPERIMENTAL)"
178c757249aSShailabh Nagar	depends on NET
179c757249aSShailabh Nagar	default n
180c757249aSShailabh Nagar	help
181c757249aSShailabh Nagar	  Export selected statistics for tasks/processes through the
182c757249aSShailabh Nagar	  generic netlink interface. Unlike BSD process accounting, the
183c757249aSShailabh Nagar	  statistics are available during the lifetime of tasks/processes as
184c757249aSShailabh Nagar	  responses to commands. Like BSD accounting, they are sent to user
185c757249aSShailabh Nagar	  space on task exit.
186c757249aSShailabh Nagar
187c757249aSShailabh Nagar	  Say N if unsure.
188c757249aSShailabh Nagar
189ca74e92bSShailabh Nagarconfig TASK_DELAY_ACCT
190ca74e92bSShailabh Nagar	bool "Enable per-task delay accounting (EXPERIMENTAL)"
1916f44993fSShailabh Nagar	depends on TASKSTATS
192ca74e92bSShailabh Nagar	help
193ca74e92bSShailabh Nagar	  Collect information on time spent by a task waiting for system
194ca74e92bSShailabh Nagar	  resources like cpu, synchronous block I/O completion and swapping
195ca74e92bSShailabh Nagar	  in pages. Such statistics can help in setting a task's priorities
196ca74e92bSShailabh Nagar	  relative to other tasks for cpu, io, rss limits etc.
197ca74e92bSShailabh Nagar
198ca74e92bSShailabh Nagar	  Say N if unsure.
199ca74e92bSShailabh Nagar
20018f705f4SAlexey Dobriyanconfig TASK_XACCT
20118f705f4SAlexey Dobriyan	bool "Enable extended accounting over taskstats (EXPERIMENTAL)"
20218f705f4SAlexey Dobriyan	depends on TASKSTATS
20318f705f4SAlexey Dobriyan	help
20418f705f4SAlexey Dobriyan	  Collect extended task accounting data and send the data
20518f705f4SAlexey Dobriyan	  to userland for processing over the taskstats interface.
20618f705f4SAlexey Dobriyan
20718f705f4SAlexey Dobriyan	  Say N if unsure.
20818f705f4SAlexey Dobriyan
20918f705f4SAlexey Dobriyanconfig TASK_IO_ACCOUNTING
21018f705f4SAlexey Dobriyan	bool "Enable per-task storage I/O accounting (EXPERIMENTAL)"
21118f705f4SAlexey Dobriyan	depends on TASK_XACCT
21218f705f4SAlexey Dobriyan	help
21318f705f4SAlexey Dobriyan	  Collect information on the number of bytes of storage I/O which this
21418f705f4SAlexey Dobriyan	  task has caused.
21518f705f4SAlexey Dobriyan
21618f705f4SAlexey Dobriyan	  Say N if unsure.
21718f705f4SAlexey Dobriyan
2181da177e4SLinus Torvaldsconfig AUDIT
2191da177e4SLinus Torvalds	bool "Auditing support"
220804a6a49SChris Wright	depends on NET
2211da177e4SLinus Torvalds	help
2221da177e4SLinus Torvalds	  Enable auditing infrastructure that can be used with another
2231da177e4SLinus Torvalds	  kernel subsystem, such as SELinux (which requires this for
2241da177e4SLinus Torvalds	  logging of avc messages output).  Does not do system-call
2251da177e4SLinus Torvalds	  auditing without CONFIG_AUDITSYSCALL.
2261da177e4SLinus Torvalds
2271da177e4SLinus Torvaldsconfig AUDITSYSCALL
2281da177e4SLinus Torvalds	bool "Enable system-call auditing support"
2291322b9deSYuichi Nakamura	depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64|| SUPERH)
2301da177e4SLinus Torvalds	default y if SECURITY_SELINUX
2311da177e4SLinus Torvalds	help
2321da177e4SLinus Torvalds	  Enable low-overhead system-call auditing infrastructure that
2331da177e4SLinus Torvalds	  can be used independently or with another kernel subsystem,
234f368c07dSAmy Griffis	  such as SELinux.  To use audit's filesystem watch feature, please
235f368c07dSAmy Griffis	  ensure that INOTIFY is configured.
2361da177e4SLinus Torvalds
23774c3cbe3SAl Viroconfig AUDIT_TREE
23874c3cbe3SAl Viro	def_bool y
23974c3cbe3SAl Viro	depends on AUDITSYSCALL && INOTIFY
24074c3cbe3SAl Viro
2411da177e4SLinus Torvaldsconfig IKCONFIG
242f2443ab6SRoss Biro	tristate "Kernel .config support"
2431da177e4SLinus Torvalds	---help---
2441da177e4SLinus Torvalds	  This option enables the complete Linux kernel ".config" file
2451da177e4SLinus Torvalds	  contents to be saved in the kernel. It provides documentation
2461da177e4SLinus Torvalds	  of which kernel options are used in a running kernel or in an
2471da177e4SLinus Torvalds	  on-disk kernel.  This information can be extracted from the kernel
2481da177e4SLinus Torvalds	  image file with the script scripts/extract-ikconfig and used as
2491da177e4SLinus Torvalds	  input to rebuild the current kernel or to build another kernel.
2501da177e4SLinus Torvalds	  It can also be extracted from a running kernel by reading
2511da177e4SLinus Torvalds	  /proc/config.gz if enabled (below).
2521da177e4SLinus Torvalds
2531da177e4SLinus Torvaldsconfig IKCONFIG_PROC
2541da177e4SLinus Torvalds	bool "Enable access to .config through /proc/config.gz"
2551da177e4SLinus Torvalds	depends on IKCONFIG && PROC_FS
2561da177e4SLinus Torvalds	---help---
2571da177e4SLinus Torvalds	  This option enables access to the kernel configuration file
2581da177e4SLinus Torvalds	  through /proc/config.gz.
2591da177e4SLinus Torvalds
260794543a2SAlistair John Strachanconfig LOG_BUF_SHIFT
261794543a2SAlistair John Strachan	int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
262794543a2SAlistair John Strachan	range 12 21
263f17a32e9SAdrian Bunk	default 17
264794543a2SAlistair John Strachan	help
265794543a2SAlistair John Strachan	  Select kernel log buffer size as a power of 2.
266f17a32e9SAdrian Bunk	  Examples:
267f17a32e9SAdrian Bunk	  	     17 => 128 KB
268f17a32e9SAdrian Bunk		     16 => 64 KB
269f17a32e9SAdrian Bunk	             15 => 32 KB
270f17a32e9SAdrian Bunk	             14 => 16 KB
271794543a2SAlistair John Strachan		     13 =>  8 KB
272794543a2SAlistair John Strachan		     12 =>  4 KB
273794543a2SAlistair John Strachan
274ddbcc7e8SPaul Menageconfig CGROUPS
275ddbcc7e8SPaul Menage	bool "Control Group support"
276ddbcc7e8SPaul Menage	help
277ddbcc7e8SPaul Menage	  This option will let you use process cgroup subsystems
278ddbcc7e8SPaul Menage	  such as Cpusets
279ddbcc7e8SPaul Menage
280ddbcc7e8SPaul Menage	  Say N if unsure.
281ddbcc7e8SPaul Menage
282006cb992SPaul Menageconfig CGROUP_DEBUG
283006cb992SPaul Menage	bool "Example debug cgroup subsystem"
284006cb992SPaul Menage	depends on CGROUPS
285418d7d87SPaul Menage	default n
286006cb992SPaul Menage	help
287006cb992SPaul Menage	  This option enables a simple cgroup subsystem that
288006cb992SPaul Menage	  exports useful debugging information about the cgroups
289006cb992SPaul Menage	  framework
290006cb992SPaul Menage
291006cb992SPaul Menage	  Say N if unsure
292006cb992SPaul Menage
293858d72eaSSerge E. Hallynconfig CGROUP_NS
294858d72eaSSerge E. Hallyn        bool "Namespace cgroup subsystem"
295858d72eaSSerge E. Hallyn        depends on CGROUPS
296858d72eaSSerge E. Hallyn        help
297858d72eaSSerge E. Hallyn          Provides a simple namespace cgroup subsystem to
298858d72eaSSerge E. Hallyn          provide hierarchical naming of sets of namespaces,
299858d72eaSSerge E. Hallyn          for instance virtual servers and checkpoint/restart
300858d72eaSSerge E. Hallyn          jobs.
301858d72eaSSerge E. Hallyn
302*dc52ddc0SMatt Helsleyconfig CGROUP_FREEZER
303*dc52ddc0SMatt Helsley        bool "control group freezer subsystem"
304*dc52ddc0SMatt Helsley        depends on CGROUPS
305*dc52ddc0SMatt Helsley        help
306*dc52ddc0SMatt Helsley          Provides a way to freeze and unfreeze all tasks in a
307*dc52ddc0SMatt Helsley	  cgroup.
308*dc52ddc0SMatt Helsley
30908ce5f16SSerge E. Hallynconfig CGROUP_DEVICE
31008ce5f16SSerge E. Hallyn	bool "Device controller for cgroups"
31108ce5f16SSerge E. Hallyn	depends on CGROUPS && EXPERIMENTAL
31208ce5f16SSerge E. Hallyn	help
31308ce5f16SSerge E. Hallyn	  Provides a cgroup implementing whitelists for devices which
31408ce5f16SSerge E. Hallyn	  a process in the cgroup can mknod or open.
31508ce5f16SSerge E. Hallyn
3161da177e4SLinus Torvaldsconfig CPUSETS
3171da177e4SLinus Torvalds	bool "Cpuset support"
3188793d854SPaul Menage	depends on SMP && CGROUPS
3191da177e4SLinus Torvalds	help
320d9fd8a6dSRandy Dunlap	  This option will let you create and manage CPUSETs which
3211da177e4SLinus Torvalds	  allow dynamically partitioning a system into sets of CPUs and
3221da177e4SLinus Torvalds	  Memory Nodes and assigning tasks to run only within those sets.
3231da177e4SLinus Torvalds	  This is primarily useful on large SMP or NUMA systems.
3241da177e4SLinus Torvalds
3251da177e4SLinus Torvalds	  Say N if unsure.
3261da177e4SLinus Torvalds
327a5574cf6SIngo Molnar#
328a5574cf6SIngo Molnar# Architectures with an unreliable sched_clock() should select this:
329a5574cf6SIngo Molnar#
330a5574cf6SIngo Molnarconfig HAVE_UNSTABLE_SCHED_CLOCK
331a5574cf6SIngo Molnar	bool
332a5574cf6SIngo Molnar
333052f1dc7SPeter Zijlstraconfig GROUP_SCHED
334052f1dc7SPeter Zijlstra	bool "Group CPU scheduler"
335aac6abcaSParag Warudkar	depends on EXPERIMENTAL
336aac6abcaSParag Warudkar	default n
33729f59db3SSrivatsa Vaddagiri	help
338fb615581SSrivatsa Vaddagiri	  This feature lets CPU scheduler recognize task groups and control CPU
3399b5b7751SSrivatsa Vaddagiri	  bandwidth allocation to such task groups.
34029f59db3SSrivatsa Vaddagiri
341052f1dc7SPeter Zijlstraconfig FAIR_GROUP_SCHED
342052f1dc7SPeter Zijlstra	bool "Group scheduling for SCHED_OTHER"
343052f1dc7SPeter Zijlstra	depends on GROUP_SCHED
344aac6abcaSParag Warudkar	default GROUP_SCHED
34524e377a8SSrivatsa Vaddagiri
346052f1dc7SPeter Zijlstraconfig RT_GROUP_SCHED
347052f1dc7SPeter Zijlstra	bool "Group scheduling for SCHED_RR/FIFO"
348052f1dc7SPeter Zijlstra	depends on EXPERIMENTAL
349052f1dc7SPeter Zijlstra	depends on GROUP_SCHED
350052f1dc7SPeter Zijlstra	default n
351b9b158feSViktor Radnai	help
352b9b158feSViktor Radnai	  This feature lets you explicitly allocate real CPU bandwidth
353b9b158feSViktor Radnai	  to users or control groups (depending on the "Basis for grouping tasks"
354b9b158feSViktor Radnai	  setting below. If enabled, it will also make it impossible to
355b9b158feSViktor Radnai	  schedule realtime tasks for non-root users until you allocate
356b9b158feSViktor Radnai	  realtime bandwidth for them.
357b9b158feSViktor Radnai	  See Documentation/sched-rt-group.txt for more information.
358052f1dc7SPeter Zijlstra
359052f1dc7SPeter Zijlstrachoice
360052f1dc7SPeter Zijlstra	depends on GROUP_SCHED
361052f1dc7SPeter Zijlstra	prompt "Basis for grouping tasks"
362052f1dc7SPeter Zijlstra	default USER_SCHED
363052f1dc7SPeter Zijlstra
364052f1dc7SPeter Zijlstraconfig USER_SCHED
36524e377a8SSrivatsa Vaddagiri	bool "user id"
36624e377a8SSrivatsa Vaddagiri	help
36724e377a8SSrivatsa Vaddagiri	  This option will choose userid as the basis for grouping
368fb615581SSrivatsa Vaddagiri	  tasks, thus providing equal CPU bandwidth to each user.
36924e377a8SSrivatsa Vaddagiri
370052f1dc7SPeter Zijlstraconfig CGROUP_SCHED
37168318b8eSSrivatsa Vaddagiri	bool "Control groups"
37268318b8eSSrivatsa Vaddagiri 	depends on CGROUPS
37368318b8eSSrivatsa Vaddagiri 	help
37468318b8eSSrivatsa Vaddagiri	  This option allows you to create arbitrary task groups
37568318b8eSSrivatsa Vaddagiri	  using the "cgroup" pseudo filesystem and control
37668318b8eSSrivatsa Vaddagiri	  the cpu bandwidth allocated to each such task group.
37768318b8eSSrivatsa Vaddagiri	  Refer to Documentation/cgroups.txt for more information
37868318b8eSSrivatsa Vaddagiri	  on "cgroup" pseudo filesystem.
37968318b8eSSrivatsa Vaddagiri
38024e377a8SSrivatsa Vaddagiriendchoice
38124e377a8SSrivatsa Vaddagiri
382d842de87SSrivatsa Vaddagiriconfig CGROUP_CPUACCT
383d842de87SSrivatsa Vaddagiri	bool "Simple CPU accounting cgroup subsystem"
384d842de87SSrivatsa Vaddagiri	depends on CGROUPS
385d842de87SSrivatsa Vaddagiri	help
386d842de87SSrivatsa Vaddagiri	  Provides a simple Resource Controller for monitoring the
387d842de87SSrivatsa Vaddagiri	  total CPU consumed by the tasks in a cgroup
388d842de87SSrivatsa Vaddagiri
389e552b661SPavel Emelianovconfig RESOURCE_COUNTERS
390e552b661SPavel Emelianov	bool "Resource counters"
391e552b661SPavel Emelianov	help
392e552b661SPavel Emelianov	  This option enables controller independent resource accounting
393e552b661SPavel Emelianov          infrastructure that works with cgroups
394e552b661SPavel Emelianov	depends on CGROUPS
395e552b661SPavel Emelianov
396cf475ad2SBalbir Singhconfig MM_OWNER
397cf475ad2SBalbir Singh	bool
398cf475ad2SBalbir Singh
39900f0b825SBalbir Singhconfig CGROUP_MEM_RES_CTLR
40000f0b825SBalbir Singh	bool "Memory Resource Controller for Control Groups"
40100f0b825SBalbir Singh	depends on CGROUPS && RESOURCE_COUNTERS
402cf475ad2SBalbir Singh	select MM_OWNER
40300f0b825SBalbir Singh	help
40400f0b825SBalbir Singh	  Provides a memory resource controller that manages both page cache and
40500f0b825SBalbir Singh	  RSS memory.
40600f0b825SBalbir Singh
40700f0b825SBalbir Singh	  Note that setting this option increases fixed memory overhead
40800f0b825SBalbir Singh	  associated with each page of memory in the system by 4/8 bytes
40900f0b825SBalbir Singh	  and also increases cache misses because struct page on many 64bit
41000f0b825SBalbir Singh	  systems will not fit into a single cache line anymore.
41100f0b825SBalbir Singh
41200f0b825SBalbir Singh	  Only enable when you're ok with these trade offs and really
41300f0b825SBalbir Singh	  sure you need the memory resource controller.
41400f0b825SBalbir Singh
415cf475ad2SBalbir Singh	  This config option also selects MM_OWNER config option, which
416cf475ad2SBalbir Singh	  could in turn add some fork/exit overhead.
417cf475ad2SBalbir Singh
41888a22c98SKay Sieversconfig SYSFS_DEPRECATED
419d47846c5SIngo Molnar	bool
420d47846c5SIngo Molnar
421d47846c5SIngo Molnarconfig SYSFS_DEPRECATED_V2
42288a22c98SKay Sievers	bool "Create deprecated sysfs files"
4239148fe87SRandy Dunlap	depends on SYSFS
42488a22c98SKay Sievers	default y
425d47846c5SIngo Molnar	select SYSFS_DEPRECATED
42688a22c98SKay Sievers	help
42788a22c98SKay Sievers	  This option creates deprecated symlinks such as the
42888a22c98SKay Sievers	  "device"-link, the <subsystem>:<name>-link, and the
42988a22c98SKay Sievers	  "bus"-link. It may also add deprecated key in the
43088a22c98SKay Sievers	  uevent environment.
43188a22c98SKay Sievers	  None of these features or values should be used today, as
43288a22c98SKay Sievers	  they export driver core implementation details to userspace
43388a22c98SKay Sievers	  or export properties which can't be kept stable across kernel
43488a22c98SKay Sievers	  releases.
43588a22c98SKay Sievers
43688a22c98SKay Sievers	  If enabled, this option will also move any device structures
4373dde6ad8SDavid Sterba	  that belong to a class, back into the /sys/class hierarchy, in
438024440d2SGreg Kroah-Hartman	  order to support older versions of udev and some userspace
439024440d2SGreg Kroah-Hartman	  programs.
44088a22c98SKay Sievers
441024440d2SGreg Kroah-Hartman	  If you are using a distro with the most recent userspace
442024440d2SGreg Kroah-Hartman	  packages, it should be safe to say N here.
44388a22c98SKay Sievers
4448793d854SPaul Menageconfig PROC_PID_CPUSET
4458793d854SPaul Menage	bool "Include legacy /proc/<pid>/cpuset file"
4468793d854SPaul Menage	depends on CPUSETS
4478793d854SPaul Menage	default y
4488793d854SPaul Menage
449b86ff981SJens Axboeconfig RELAY
450b86ff981SJens Axboe	bool "Kernel->user space relay support (formerly relayfs)"
451b86ff981SJens Axboe	help
452b86ff981SJens Axboe	  This option enables support for relay interface support in
453b86ff981SJens Axboe	  certain file systems (such as debugfs).
454b86ff981SJens Axboe	  It is designed to provide an efficient mechanism for tools and
455b86ff981SJens Axboe	  facilities to relay large amounts of data from kernel space to
456b86ff981SJens Axboe	  user space.
457b86ff981SJens Axboe
458b86ff981SJens Axboe	  If unsure, say N.
459b86ff981SJens Axboe
460c5289a69SPavel Emelyanovconfig NAMESPACES
461c5289a69SPavel Emelyanov	bool "Namespaces support" if EMBEDDED
462c5289a69SPavel Emelyanov	default !EMBEDDED
463c5289a69SPavel Emelyanov	help
464c5289a69SPavel Emelyanov	  Provides the way to make tasks work with different objects using
465c5289a69SPavel Emelyanov	  the same id. For example same IPC id may refer to different objects
466c5289a69SPavel Emelyanov	  or same user id or pid may refer to different tasks when used in
467c5289a69SPavel Emelyanov	  different namespaces.
468c5289a69SPavel Emelyanov
46958bfdd6dSPavel Emelyanovconfig UTS_NS
47058bfdd6dSPavel Emelyanov	bool "UTS namespace"
47158bfdd6dSPavel Emelyanov	depends on NAMESPACES
47258bfdd6dSPavel Emelyanov	help
47358bfdd6dSPavel Emelyanov	  In this namespace tasks see different info provided with the
47458bfdd6dSPavel Emelyanov	  uname() system call
47558bfdd6dSPavel Emelyanov
476ae5e1b22SPavel Emelyanovconfig IPC_NS
477ae5e1b22SPavel Emelyanov	bool "IPC namespace"
478ae5e1b22SPavel Emelyanov	depends on NAMESPACES && SYSVIPC
479ae5e1b22SPavel Emelyanov	help
480ae5e1b22SPavel Emelyanov	  In this namespace tasks work with IPC ids which correspond to
481ae5e1b22SPavel Emelyanov	  different IPC objects in different namespaces
482ae5e1b22SPavel Emelyanov
483aee16ce7SPavel Emelyanovconfig USER_NS
484aee16ce7SPavel Emelyanov	bool "User namespace (EXPERIMENTAL)"
485aee16ce7SPavel Emelyanov	depends on NAMESPACES && EXPERIMENTAL
486aee16ce7SPavel Emelyanov	help
487aee16ce7SPavel Emelyanov	  This allows containers, i.e. vservers, to use user namespaces
488aee16ce7SPavel Emelyanov	  to provide different user info for different servers.
489aee16ce7SPavel Emelyanov	  If unsure, say N.
490aee16ce7SPavel Emelyanov
49174bd59bbSPavel Emelyanovconfig PID_NS
49274bd59bbSPavel Emelyanov	bool "PID Namespaces (EXPERIMENTAL)"
49374bd59bbSPavel Emelyanov	default n
49474bd59bbSPavel Emelyanov	depends on NAMESPACES && EXPERIMENTAL
49574bd59bbSPavel Emelyanov	help
49612d2b8f9SHeikki Orsila	  Support process id namespaces.  This allows having multiple
49774bd59bbSPavel Emelyanov	  process with the same pid as long as they are in different
49874bd59bbSPavel Emelyanov	  pid namespaces.  This is a building block of containers.
49974bd59bbSPavel Emelyanov
50074bd59bbSPavel Emelyanov	  Unless you want to work with an experimental feature
50174bd59bbSPavel Emelyanov	  say N here.
50274bd59bbSPavel Emelyanov
503f991633dSDimitri Gorokhovikconfig BLK_DEV_INITRD
504f991633dSDimitri Gorokhovik	bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
505f991633dSDimitri Gorokhovik	depends on BROKEN || !FRV
506f991633dSDimitri Gorokhovik	help
507f991633dSDimitri Gorokhovik	  The initial RAM filesystem is a ramfs which is loaded by the
508f991633dSDimitri Gorokhovik	  boot loader (loadlin or lilo) and that is mounted as root
509f991633dSDimitri Gorokhovik	  before the normal boot procedure. It is typically used to
510f991633dSDimitri Gorokhovik	  load modules needed to mount the "real" root file system,
511f991633dSDimitri Gorokhovik	  etc. See <file:Documentation/initrd.txt> for details.
512f991633dSDimitri Gorokhovik
513f991633dSDimitri Gorokhovik	  If RAM disk support (BLK_DEV_RAM) is also included, this
514f991633dSDimitri Gorokhovik	  also enables initial RAM disk (initrd) support and adds
515f991633dSDimitri Gorokhovik	  15 Kbytes (more on some other architectures) to the kernel size.
516f991633dSDimitri Gorokhovik
517f991633dSDimitri Gorokhovik	  If unsure say Y.
518f991633dSDimitri Gorokhovik
519c33df4eaSJean-Paul Samanif BLK_DEV_INITRD
520c33df4eaSJean-Paul Saman
521dbec4866SSam Ravnborgsource "usr/Kconfig"
522dbec4866SSam Ravnborg
523c33df4eaSJean-Paul Samanendif
524c33df4eaSJean-Paul Saman
525c45b4f1fSLinus Torvaldsconfig CC_OPTIMIZE_FOR_SIZE
52696fffeb4SIngo Molnar	bool "Optimize for size"
527c45b4f1fSLinus Torvalds	default y
528c45b4f1fSLinus Torvalds	help
529c45b4f1fSLinus Torvalds	  Enabling this option will pass "-Os" instead of "-O2" to gcc
530c45b4f1fSLinus Torvalds	  resulting in a smaller kernel.
531c45b4f1fSLinus Torvalds
532775a7229Sjkacur	  If unsure, say Y.
533c45b4f1fSLinus Torvalds
5340847062aSRandy Dunlapconfig SYSCTL
5350847062aSRandy Dunlap	bool
5360847062aSRandy Dunlap
5371da177e4SLinus Torvaldsmenuconfig EMBEDDED
5381da177e4SLinus Torvalds	bool "Configure standard kernel features (for small systems)"
5391da177e4SLinus Torvalds	help
5401da177e4SLinus Torvalds	  This option allows certain base kernel options and settings
5411da177e4SLinus Torvalds          to be disabled or tweaked. This is for specialized
5421da177e4SLinus Torvalds          environments which can tolerate a "non-standard" kernel.
5431da177e4SLinus Torvalds          Only use this if you really know what you are doing.
5441da177e4SLinus Torvalds
545ae81f9e3SChuck Ebbertconfig UID16
546ae81f9e3SChuck Ebbert	bool "Enable 16-bit UID system calls" if EMBEDDED
54709337f50SDavid S. Miller	depends on ARM || BLACKFIN || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && COMPAT) || UML || (X86_64 && IA32_EMULATION)
548ae81f9e3SChuck Ebbert	default y
549ae81f9e3SChuck Ebbert	help
550ae81f9e3SChuck Ebbert	  This enables the legacy 16-bit UID syscall wrappers.
551ae81f9e3SChuck Ebbert
552b89a8171SEric W. Biedermanconfig SYSCTL_SYSCALL
5530847062aSRandy Dunlap	bool "Sysctl syscall support" if EMBEDDED
55413bb7e37SEric W. Biederman	default y
555b89a8171SEric W. Biederman	select SYSCTL
556b89a8171SEric W. Biederman	---help---
55713bb7e37SEric W. Biederman	  sys_sysctl uses binary paths that have been found challenging
55813bb7e37SEric W. Biederman	  to properly maintain and use.  The interface in /proc/sys
55913bb7e37SEric W. Biederman	  using paths with ascii names is now the primary path to this
56013bb7e37SEric W. Biederman	  information.
561b89a8171SEric W. Biederman
56213bb7e37SEric W. Biederman	  Almost nothing using the binary sysctl interface so if you are
56313bb7e37SEric W. Biederman	  trying to save some space it is probably safe to disable this,
56413bb7e37SEric W. Biederman	  making your kernel marginally smaller.
565b89a8171SEric W. Biederman
56613bb7e37SEric W. Biederman	  If unsure say Y here.
567ae81f9e3SChuck Ebbert
5681da177e4SLinus Torvaldsconfig KALLSYMS
569979c6a1eSJesper Juhl	 bool "Load all symbols for debugging/ksymoops" if EMBEDDED
5701da177e4SLinus Torvalds	 default y
5711da177e4SLinus Torvalds	 help
5721da177e4SLinus Torvalds	   Say Y here to let the kernel print out symbolic crash information and
5731da177e4SLinus Torvalds	   symbolic stack backtraces. This increases the size of the kernel
5741da177e4SLinus Torvalds	   somewhat, as all symbols have to be loaded into the kernel image.
5751da177e4SLinus Torvalds
5761da177e4SLinus Torvaldsconfig KALLSYMS_ALL
5771da177e4SLinus Torvalds	bool "Include all symbols in kallsyms"
5781da177e4SLinus Torvalds	depends on DEBUG_KERNEL && KALLSYMS
5791da177e4SLinus Torvalds	help
5801da177e4SLinus Torvalds	   Normally kallsyms only contains the symbols of functions, for nicer
5811da177e4SLinus Torvalds	   OOPS messages.  Some debuggers can use kallsyms for other
582f9f97bc0SJesper Juhl	   symbols too: say Y here to include all symbols, if you need them
583f9f97bc0SJesper Juhl	   and you don't care about adding 300k to the size of your kernel.
5841da177e4SLinus Torvalds
5851da177e4SLinus Torvalds	   Say N.
5861da177e4SLinus Torvalds
5871da177e4SLinus Torvaldsconfig KALLSYMS_EXTRA_PASS
5881da177e4SLinus Torvalds	bool "Do an extra kallsyms pass"
5891da177e4SLinus Torvalds	depends on KALLSYMS
5901da177e4SLinus Torvalds	help
5911da177e4SLinus Torvalds	   If kallsyms is not working correctly, the build will fail with
5921da177e4SLinus Torvalds	   inconsistent kallsyms data.  If that occurs, log a bug report and
5931da177e4SLinus Torvalds	   turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
5941da177e4SLinus Torvalds	   Always say N here unless you find a bug in kallsyms, which must be
5951da177e4SLinus Torvalds	   reported.  KALLSYMS_EXTRA_PASS is only a temporary workaround while
5961da177e4SLinus Torvalds	   you wait for kallsyms to be fixed.
5971da177e4SLinus Torvalds
598d59745ceSMatt Mackall
599712f47ceSGreg Kroah-Hartmanconfig HOTPLUG
600712f47ceSGreg Kroah-Hartman	bool "Support for hot-pluggable devices" if EMBEDDED
601712f47ceSGreg Kroah-Hartman	default y
602712f47ceSGreg Kroah-Hartman	help
603712f47ceSGreg Kroah-Hartman	  This option is provided for the case where no hotplug or uevent
604712f47ceSGreg Kroah-Hartman	  capabilities is wanted by the kernel.  You should only consider
605712f47ceSGreg Kroah-Hartman	  disabling this option for embedded systems that do not use modules, a
606712f47ceSGreg Kroah-Hartman	  dynamic /dev tree, or dynamic device discovery.  Just say Y.
607712f47ceSGreg Kroah-Hartman
608d59745ceSMatt Mackallconfig PRINTK
609d59745ceSMatt Mackall	default y
610d59745ceSMatt Mackall	bool "Enable support for printk" if EMBEDDED
611d59745ceSMatt Mackall	help
612d59745ceSMatt Mackall	  This option enables normal printk support. Removing it
613d59745ceSMatt Mackall	  eliminates most of the message strings from the kernel image
614d59745ceSMatt Mackall	  and makes the kernel more or less silent. As this makes it
615d59745ceSMatt Mackall	  very difficult to diagnose system problems, saying N here is
616d59745ceSMatt Mackall	  strongly discouraged.
617d59745ceSMatt Mackall
618c8538a7aSMatt Mackallconfig BUG
619c8538a7aSMatt Mackall	bool "BUG() support" if EMBEDDED
620c8538a7aSMatt Mackall	default y
621c8538a7aSMatt Mackall	help
622c8538a7aSMatt Mackall          Disabling this option eliminates support for BUG and WARN, reducing
623c8538a7aSMatt Mackall          the size of your kernel image and potentially quietly ignoring
624c8538a7aSMatt Mackall          numerous fatal conditions. You should only consider disabling this
625c8538a7aSMatt Mackall          option for embedded systems with no facilities for reporting errors.
626c8538a7aSMatt Mackall          Just say Y.
627c8538a7aSMatt Mackall
628708e9a79SMatt Mackallconfig ELF_CORE
629708e9a79SMatt Mackall	default y
630708e9a79SMatt Mackall	bool "Enable ELF core dumps" if EMBEDDED
631708e9a79SMatt Mackall	help
632708e9a79SMatt Mackall	  Enable support for generating core dumps. Disabling saves about 4k.
633708e9a79SMatt Mackall
634e5e1d3cbSStas Sergeevconfig PCSPKR_PLATFORM
635e5e1d3cbSStas Sergeev	bool "Enable PC-Speaker support" if EMBEDDED
636e5e1d3cbSStas Sergeev	depends on ALPHA || X86 || MIPS || PPC_PREP || PPC_CHRP || PPC_PSERIES
637e5e1d3cbSStas Sergeev	default y
638e5e1d3cbSStas Sergeev	help
639e5e1d3cbSStas Sergeev          This option allows to disable the internal PC-Speaker
640e5e1d3cbSStas Sergeev          support, saving some memory.
641e5e1d3cbSStas Sergeev
64232a93233SIngo Molnarconfig COMPAT_BRK
64332a93233SIngo Molnar	bool "Disable heap randomization"
64432a93233SIngo Molnar	default y
64532a93233SIngo Molnar	help
64632a93233SIngo Molnar	  Randomizing heap placement makes heap exploits harder, but it
64732a93233SIngo Molnar	  also breaks ancient binaries (including anything libc5 based).
64832a93233SIngo Molnar	  This option changes the bootup default to heap randomization
64932a93233SIngo Molnar	  disabled, and can be overriden runtime by setting
65032a93233SIngo Molnar	  /proc/sys/kernel/randomize_va_space to 2.
65132a93233SIngo Molnar
652166124fdSIngo Molnar	  On non-ancient distros (post-2000 ones) N is usually a safe choice.
65332a93233SIngo Molnar
6541da177e4SLinus Torvaldsconfig BASE_FULL
6551da177e4SLinus Torvalds	default y
6561da177e4SLinus Torvalds	bool "Enable full-sized data structures for core" if EMBEDDED
6571da177e4SLinus Torvalds	help
6581da177e4SLinus Torvalds	  Disabling this option reduces the size of miscellaneous core
6591da177e4SLinus Torvalds	  kernel data structures. This saves memory on small machines,
6601da177e4SLinus Torvalds	  but may reduce performance.
6611da177e4SLinus Torvalds
6621da177e4SLinus Torvaldsconfig FUTEX
6631da177e4SLinus Torvalds	bool "Enable futex support" if EMBEDDED
6641da177e4SLinus Torvalds	default y
66523f78d4aSIngo Molnar	select RT_MUTEXES
6661da177e4SLinus Torvalds	help
6671da177e4SLinus Torvalds	  Disabling this option will cause the kernel to be built without
6681da177e4SLinus Torvalds	  support for "fast userspace mutexes".  The resulting kernel may not
6691da177e4SLinus Torvalds	  run glibc-based applications correctly.
6701da177e4SLinus Torvalds
6715dc8bf81SDavide Libenziconfig ANON_INODES
672448e3ceeSAdrian Bunk	bool
6735dc8bf81SDavide Libenzi
6741da177e4SLinus Torvaldsconfig EPOLL
6751da177e4SLinus Torvalds	bool "Enable eventpoll support" if EMBEDDED
6761da177e4SLinus Torvalds	default y
677448e3ceeSAdrian Bunk	select ANON_INODES
6781da177e4SLinus Torvalds	help
6791da177e4SLinus Torvalds	  Disabling this option will cause the kernel to be built without
6801da177e4SLinus Torvalds	  support for epoll family of system calls.
6811da177e4SLinus Torvalds
682fba2afaaSDavide Libenziconfig SIGNALFD
683fba2afaaSDavide Libenzi	bool "Enable signalfd() system call" if EMBEDDED
684448e3ceeSAdrian Bunk	select ANON_INODES
685fba2afaaSDavide Libenzi	default y
686fba2afaaSDavide Libenzi	help
687fba2afaaSDavide Libenzi	  Enable the signalfd() system call that allows to receive signals
688fba2afaaSDavide Libenzi	  on a file descriptor.
689fba2afaaSDavide Libenzi
690fba2afaaSDavide Libenzi	  If unsure, say Y.
691fba2afaaSDavide Libenzi
692b215e283SDavide Libenziconfig TIMERFD
693b215e283SDavide Libenzi	bool "Enable timerfd() system call" if EMBEDDED
694448e3ceeSAdrian Bunk	select ANON_INODES
695b215e283SDavide Libenzi	default y
696b215e283SDavide Libenzi	help
697b215e283SDavide Libenzi	  Enable the timerfd() system call that allows to receive timer
698b215e283SDavide Libenzi	  events on a file descriptor.
699b215e283SDavide Libenzi
700b215e283SDavide Libenzi	  If unsure, say Y.
701b215e283SDavide Libenzi
702e1ad7468SDavide Libenziconfig EVENTFD
703e1ad7468SDavide Libenzi	bool "Enable eventfd() system call" if EMBEDDED
704448e3ceeSAdrian Bunk	select ANON_INODES
705e1ad7468SDavide Libenzi	default y
706e1ad7468SDavide Libenzi	help
707e1ad7468SDavide Libenzi	  Enable the eventfd() system call that allows to receive both
708e1ad7468SDavide Libenzi	  kernel notification (ie. KAIO) or userspace notifications.
709e1ad7468SDavide Libenzi
710e1ad7468SDavide Libenzi	  If unsure, say Y.
711e1ad7468SDavide Libenzi
7121da177e4SLinus Torvaldsconfig SHMEM
7131da177e4SLinus Torvalds	bool "Use full shmem filesystem" if EMBEDDED
7141da177e4SLinus Torvalds	default y
7151da177e4SLinus Torvalds	depends on MMU
7161da177e4SLinus Torvalds	help
7171da177e4SLinus Torvalds	  The shmem is an internal filesystem used to manage shared memory.
7181da177e4SLinus Torvalds	  It is backed by swap and manages resource limits. It is also exported
7191da177e4SLinus Torvalds	  to userspace as tmpfs if TMPFS is enabled. Disabling this
7201da177e4SLinus Torvalds	  option replaces shmem and tmpfs with the much simpler ramfs code,
7211da177e4SLinus Torvalds	  which may be appropriate on small systems without swap.
7221da177e4SLinus Torvalds
723ebf3f09cSThomas Petazzoniconfig AIO
724ebf3f09cSThomas Petazzoni	bool "Enable AIO support" if EMBEDDED
725ebf3f09cSThomas Petazzoni	default y
726ebf3f09cSThomas Petazzoni	help
727ebf3f09cSThomas Petazzoni	  This option enables POSIX asynchronous I/O which may by used
728ebf3f09cSThomas Petazzoni          by some high performance threaded applications. Disabling
729ebf3f09cSThomas Petazzoni          this option saves about 7k.
730ebf3f09cSThomas Petazzoni
731f8891e5eSChristoph Lameterconfig VM_EVENT_COUNTERS
732f8891e5eSChristoph Lameter	default y
733f8891e5eSChristoph Lameter	bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
734f8891e5eSChristoph Lameter	help
7352aea4fb6SPaul Jackson	  VM event counters are needed for event counts to be shown.
7362aea4fb6SPaul Jackson	  This option allows the disabling of the VM event counters
7372aea4fb6SPaul Jackson	  on EMBEDDED systems.  /proc/vmstat will only show page counts
7382aea4fb6SPaul Jackson	  if VM event counters are disabled.
739f8891e5eSChristoph Lameter
74041ecc55bSChristoph Lameterconfig SLUB_DEBUG
74141ecc55bSChristoph Lameter	default y
74241ecc55bSChristoph Lameter	bool "Enable SLUB debugging support" if EMBEDDED
743f6acb635SChristoph Lameter	depends on SLUB && SYSFS
74441ecc55bSChristoph Lameter	help
74541ecc55bSChristoph Lameter	  SLUB has extensive debug support features. Disabling these can
74641ecc55bSChristoph Lameter	  result in significant savings in code size. This also disables
74741ecc55bSChristoph Lameter	  SLUB sysfs support. /sys/slab will not exist and there will be
74841ecc55bSChristoph Lameter	  no support for cache validation etc.
74941ecc55bSChristoph Lameter
75081819f0fSChristoph Lameterchoice
75181819f0fSChristoph Lameter	prompt "Choose SLAB allocator"
752a0acd820SChristoph Lameter	default SLUB
75381819f0fSChristoph Lameter	help
75481819f0fSChristoph Lameter	   This option allows to select a slab allocator.
75581819f0fSChristoph Lameter
75681819f0fSChristoph Lameterconfig SLAB
75781819f0fSChristoph Lameter	bool "SLAB"
75881819f0fSChristoph Lameter	help
75981819f0fSChristoph Lameter	  The regular slab allocator that is established and known to work
76034013886SChristoph Lameter	  well in all environments. It organizes cache hot objects in
76181819f0fSChristoph Lameter	  per cpu and per node queues. SLAB is the default choice for
76234013886SChristoph Lameter	  a slab allocator.
76381819f0fSChristoph Lameter
76481819f0fSChristoph Lameterconfig SLUB
76581819f0fSChristoph Lameter	bool "SLUB (Unqueued Allocator)"
76681819f0fSChristoph Lameter	help
76781819f0fSChristoph Lameter	   SLUB is a slab allocator that minimizes cache line usage
76881819f0fSChristoph Lameter	   instead of managing queues of cached objects (SLAB approach).
76981819f0fSChristoph Lameter	   Per cpu caching is realized using slabs of objects instead
77081819f0fSChristoph Lameter	   of queues of objects. SLUB can use memory efficiently
77134013886SChristoph Lameter	   and has enhanced diagnostics.
77281819f0fSChristoph Lameter
77381819f0fSChristoph Lameterconfig SLOB
77484a01c2fSPaul Mundt	depends on EMBEDDED
77581819f0fSChristoph Lameter	bool "SLOB (Simple Allocator)"
77681819f0fSChristoph Lameter	help
77737291458SMatt Mackall	   SLOB replaces the stock allocator with a drastically simpler
77837291458SMatt Mackall	   allocator. SLOB is generally more space efficient but
77937291458SMatt Mackall	   does not perform as well on large systems.
78081819f0fSChristoph Lameter
78181819f0fSChristoph Lameterendchoice
78281819f0fSChristoph Lameter
783125e5645SMathieu Desnoyersconfig PROFILING
784125e5645SMathieu Desnoyers	bool "Profiling support (EXPERIMENTAL)"
785125e5645SMathieu Desnoyers	help
786125e5645SMathieu Desnoyers	  Say Y here to enable the extended profiling support mechanisms used
787125e5645SMathieu Desnoyers	  by profilers such as OProfile.
788125e5645SMathieu Desnoyers
789125e5645SMathieu Desnoyersconfig MARKERS
790125e5645SMathieu Desnoyers	bool "Activate markers"
791125e5645SMathieu Desnoyers	help
792125e5645SMathieu Desnoyers	  Place an empty function call at each marker site. Can be
793125e5645SMathieu Desnoyers	  dynamically changed for a probe function.
794125e5645SMathieu Desnoyers
795fb32e03fSMathieu Desnoyerssource "arch/Kconfig"
796fb32e03fSMathieu Desnoyers
7971da177e4SLinus Torvaldsendmenu		# General setup
7981da177e4SLinus Torvalds
799ee7e5516SDmitry Baryshkovconfig HAVE_GENERIC_DMA_COHERENT
800ee7e5516SDmitry Baryshkov	bool
801ee7e5516SDmitry Baryshkov	default n
802ee7e5516SDmitry Baryshkov
803158a9624SLinus Torvaldsconfig SLABINFO
804158a9624SLinus Torvalds	bool
805158a9624SLinus Torvalds	depends on PROC_FS
8060f389ec6SChristoph Lameter	depends on SLAB || SLUB_DEBUG
807158a9624SLinus Torvalds	default y
808158a9624SLinus Torvalds
809ae81f9e3SChuck Ebbertconfig RT_MUTEXES
810ae81f9e3SChuck Ebbert	boolean
811ae81f9e3SChuck Ebbert	select PLIST
812ae81f9e3SChuck Ebbert
8131da177e4SLinus Torvaldsconfig TINY_SHMEM
8141da177e4SLinus Torvalds	default !SHMEM
8151da177e4SLinus Torvalds	bool
8161da177e4SLinus Torvalds
8171da177e4SLinus Torvaldsconfig BASE_SMALL
8181da177e4SLinus Torvalds	int
8191da177e4SLinus Torvalds	default 0 if BASE_FULL
8201da177e4SLinus Torvalds	default 1 if !BASE_FULL
8211da177e4SLinus Torvalds
82266da5733SJan Engelhardtmenuconfig MODULES
8231da177e4SLinus Torvalds	bool "Enable loadable module support"
8241da177e4SLinus Torvalds	help
8251da177e4SLinus Torvalds	  Kernel modules are small pieces of compiled code which can
8261da177e4SLinus Torvalds	  be inserted in the running kernel, rather than being
8271da177e4SLinus Torvalds	  permanently built into the kernel.  You use the "modprobe"
8281da177e4SLinus Torvalds	  tool to add (and sometimes remove) them.  If you say Y here,
8291da177e4SLinus Torvalds	  many parts of the kernel can be built as modules (by
8301da177e4SLinus Torvalds	  answering M instead of Y where indicated): this is most
8311da177e4SLinus Torvalds	  useful for infrequently used options which are not required
8321da177e4SLinus Torvalds	  for booting.  For more information, see the man pages for
8331da177e4SLinus Torvalds	  modprobe, lsmod, modinfo, insmod and rmmod.
8341da177e4SLinus Torvalds
8351da177e4SLinus Torvalds	  If you say Y here, you will need to run "make
8361da177e4SLinus Torvalds	  modules_install" to put the modules under /lib/modules/
8371da177e4SLinus Torvalds	  where modprobe can find them (you may need to be root to do
8381da177e4SLinus Torvalds	  this).
8391da177e4SLinus Torvalds
8401da177e4SLinus Torvalds	  If unsure, say Y.
8411da177e4SLinus Torvalds
8420b0de144SRobert P. J. Dayif MODULES
8430b0de144SRobert P. J. Day
844826e4506SLinus Torvaldsconfig MODULE_FORCE_LOAD
845826e4506SLinus Torvalds	bool "Forced module loading"
846826e4506SLinus Torvalds	default n
847826e4506SLinus Torvalds	help
84891e37a79SRusty Russell	  Allow loading of modules without version information (ie. modprobe
84991e37a79SRusty Russell	  --force).  Forced module loading sets the 'F' (forced) taint flag and
85091e37a79SRusty Russell	  is usually a really bad idea.
851826e4506SLinus Torvalds
8521da177e4SLinus Torvaldsconfig MODULE_UNLOAD
8531da177e4SLinus Torvalds	bool "Module unloading"
8541da177e4SLinus Torvalds	help
8551da177e4SLinus Torvalds	  Without this option you will not be able to unload any
8561da177e4SLinus Torvalds	  modules (note that some modules may not be unloadable
857f7f5b675SDenys Vlasenko	  anyway), which makes your kernel smaller, faster
858f7f5b675SDenys Vlasenko	  and simpler.  If unsure, say Y.
8591da177e4SLinus Torvalds
8601da177e4SLinus Torvaldsconfig MODULE_FORCE_UNLOAD
8611da177e4SLinus Torvalds	bool "Forced module unloading"
8621da177e4SLinus Torvalds	depends on MODULE_UNLOAD && EXPERIMENTAL
8631da177e4SLinus Torvalds	help
8641da177e4SLinus Torvalds	  This option allows you to force a module to unload, even if the
8651da177e4SLinus Torvalds	  kernel believes it is unsafe: the kernel will remove the module
8661da177e4SLinus Torvalds	  without waiting for anyone to stop using it (using the -f option to
8671da177e4SLinus Torvalds	  rmmod).  This is mainly for kernel developers and desperate users.
8681da177e4SLinus Torvalds	  If unsure, say N.
8691da177e4SLinus Torvalds
8701da177e4SLinus Torvaldsconfig MODVERSIONS
8710d541643SSam Ravnborg	bool "Module versioning support"
8721da177e4SLinus Torvalds	help
8731da177e4SLinus Torvalds	  Usually, you have to use modules compiled with your kernel.
8741da177e4SLinus Torvalds	  Saying Y here makes it sometimes possible to use modules
8751da177e4SLinus Torvalds	  compiled for different kernels, by adding enough information
8761da177e4SLinus Torvalds	  to the modules to (hopefully) spot any changes which would
8771da177e4SLinus Torvalds	  make them incompatible with the kernel you are running.  If
8781da177e4SLinus Torvalds	  unsure, say N.
8791da177e4SLinus Torvalds
8801da177e4SLinus Torvaldsconfig MODULE_SRCVERSION_ALL
8811da177e4SLinus Torvalds	bool "Source checksum for all modules"
8821da177e4SLinus Torvalds	help
8831da177e4SLinus Torvalds	  Modules which contain a MODULE_VERSION get an extra "srcversion"
8841da177e4SLinus Torvalds	  field inserted into their modinfo section, which contains a
8851da177e4SLinus Torvalds    	  sum of the source files which made it.  This helps maintainers
8861da177e4SLinus Torvalds	  see exactly which source was used to build a module (since
8871da177e4SLinus Torvalds	  others sometimes change the module source without updating
8881da177e4SLinus Torvalds	  the version).  With this option, such a "srcversion" field
8891da177e4SLinus Torvalds	  will be created for all modules.  If unsure, say N.
8901da177e4SLinus Torvalds
8911da177e4SLinus Torvaldsconfig KMOD
892baabaae9SJohannes Berg	def_bool y
8931da177e4SLinus Torvalds	help
894baabaae9SJohannes Berg	  This is being removed soon.  These days, CONFIG_MODULES
895baabaae9SJohannes Berg	  implies CONFIG_KMOD, so use that instead.
8961da177e4SLinus Torvalds
8970b0de144SRobert P. J. Dayendif # MODULES
8980b0de144SRobert P. J. Day
8991da177e4SLinus Torvaldsconfig STOP_MACHINE
9001da177e4SLinus Torvalds	bool
9011da177e4SLinus Torvalds	default y
9021da177e4SLinus Torvalds	depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
9031da177e4SLinus Torvalds	help
9041da177e4SLinus Torvalds	  Need stop_machine() primitive.
9053a65dfe8SJens Axboe
9063a65dfe8SJens Axboesource "block/Kconfig"
907e98c3202SAvi Kivity
908e98c3202SAvi Kivityconfig PREEMPT_NOTIFIERS
909e98c3202SAvi Kivity	bool
910e260be67SPaul E. McKenney
911e260be67SPaul E. McKenneyconfig CLASSIC_RCU
91221bbb39cSPaul E. McKenney	def_bool !PREEMPT_RCU
913e260be67SPaul E. McKenney	help
914e260be67SPaul E. McKenney	  This option selects the classic RCU implementation that is
915e260be67SPaul E. McKenney	  designed for best read-side performance on non-realtime
91621bbb39cSPaul E. McKenney	  systems.  Classic RCU is the default.  Note that the
91721bbb39cSPaul E. McKenney	  PREEMPT_RCU symbol is used to select/deselect this option.
918